KR101362886B1 - Electrode paste composition and Electrode Produced Thereby - Google Patents

Abstract

The present invention relates to a conductive paste composition and an electrode formed therefrom. More specifically, the present invention includes two or more epoxy-based binder resins and a bifunctional (meth) acrylate compound, thereby having excellent electrical properties and having a high peel strength for the conductive adhesive film and a conductive paste composition formed therefrom It is about.

Description

Electroconductive paste composition and electrode formed therefrom {Electrode paste composition and Electrode Produced Thereby}

The present invention relates to a conductive paste composition and an electrode formed therefrom. More specifically, the present invention includes two or more epoxy-based binder resins and bifunctional (meth) acrylate compounds, thereby having excellent electrical properties and having a high peel strength for the conductive adhesive film, and a conductive paste composition formed therefrom It is about.

In a heterojunction with intrinsic thin layer (HIT) solar cell or a thin film solar cell using a transparent electrode containing indium tin oxide (ITO), a change in cell characteristics at high temperature has been a problem. In order to overcome this problem, efforts have been made to develop electrode pastes having excellent low-temperature curing electrical conductivity.

In general, in the plastic type solar cell, the electrode is known to form an electrode by reacting Ag with a silicon interface in the solar cell after the anti-reflection film layer is etched by the glass component in the paste. Therefore, in order to improve the performance of the electrode of the solar cell, a low contact resistance for efficiently transferring the charge-hole pairs in the solar cell to the finger electrode and a line resistance for lossless transfer of electricity transferred to the finger electrode to the bus-bar electrode Two factors are important. In the case of a HIT solar cell or a thin film solar cell in which a transparent conductive film is formed, the contact resistance of the surface tends to be influenced by the optimum surface contact between the transparent conductive layer (TCO layer) and the paste.

Accordingly, in order to increase the efficiency of solar cells, HIT solar cells or thin film solar cells in which transparent conductive films are formed, as well as plastic type solar cells, have been continuously developing conductive pastes for solar cells having excellent line resistance and low contact resistance. Conventional conductive paste compositions have mostly been a technique for optimizing the electrical properties by changing the size, shape or type of the conductive powder. However, the conductive powders developed to date have not only limited materials and sizes, but also limited shapes to spheres, plates, and the like, and thus have been limited in improving electrical properties.

An object of the present invention is to provide a conductive paste composition having high peel strength and low contact resistance and low line resistance.

Another object of the present invention is to provide an electrode formed from the conductive paste composition.

One aspect of the invention relates to a conductive paste composition.

In one embodiment, the composition may include two or more epoxy-based binder resins, bifunctional (meth) acrylate compounds, conductive powders, curing agents and solvents.

In one embodiment, the bifunctional (meth) acrylate compound is 1,6-hexanedioldiacrylate, 1,9-nonanedioldiacrylate, 1,10-decanedioldiacrylate, dipropylene glycol diacryl Rate, tripropylene glycol diacrylate, polyethylene glycol diacrylate, polypropylene glycol diacrylate, polybutylene glycol diacrylate, 2-hydroxy-1-acryloxy-3- metharyl oxypropane, propoxylay Tide ethoxylated bis-A diacrylate, 2,2 bis [4- (acryloxy polyethoxy) phenyl] propane, 2,2-bis [4- (acryloxy diethoxy) phenyl] propane, 9, Consisting of 9-bis [4- (2-acryloyloxy ethoxy) phenyl] fluorene, 2,2-bis [4- (acryloxy polypropoxy) phenyl] propane and tricyclodecane dimethanol diacrylate It may be one or more selected from the group.

 In embodiments, the bifunctional (meth) acrylate compound may be included in 0.1 to 10% by weight of the conductive paste composition.

In one embodiment, the epoxy-based binder resin is an epoxy-based binder resin (A) having a melt viscosity of less than 1.5 Pa.s at 150 ° C, and an epoxy-based binder resin having a melt viscosity of 10 Pa.s or less at 25 ° C ( B).

In one embodiment, the epoxy-based binder resin may include a cresol novolak-type resin and a bisphenol F-type resin.

Another aspect of the invention relates to an electrode formed from the conductive paste composition.

The present invention provides a conductive paste composition for producing an electrode having low contact resistance and line resistance and high peel strength. The present invention also provides an electrode formed from the conductive paste composition.

Epoxy binder resin

In the conductive paste composition of the present invention, the epoxy-based binder resin may include two or more different resins.

Specifically, the epoxy binder resin has a melt viscosity of 1.5 Pa · s or less at 150 ° C., preferably 0.5 to 1.5 Pa · s, and a melt viscosity of 10 Pa · s or less at 25 ° C., preferably. Makes It may contain one or more types of epoxy-based binder resin (B) of 0.2 to 5 Pa.s.

The said epoxy binder resin (A) contains 1 or more types chosen from the group which consists of a cresol novolak-type resin, a biphenyl type resin, a biphenyl mixed resin, a naphthalene type resin, and a dicyclopentadiene type resin, for example. You can, but are not limited to this.

The epoxy binder resin (B) may be, for example, one or more selected from the group consisting of bisphenol F resin and bisphenol A resin, but is not limited thereto.

Preferably, as the epoxy binder resin, cresol novolac resins and bisphenol F resins may be used.

The epoxy binder resin (A) and the epoxy binder resin (B) may be included in a weight ratio of 1: 0.1 to 1:14. Within this range, the peel strength for the conductive adhesive film can be high and the electrical properties can be improved. Preferably it may be included in the weight ratio of 1: 0.2 to 1: 5, more preferably 1: 0.2 to 1: 1.25.

Epoxy-based binder resin may be used a weight average molecular weight of 2,000 to 4,000 g / mol, preferably a weight average molecular weight of 2,500 to 3,500 g / mol can be used.

Epoxy-based binder resin may be included in 1 to 10% by weight of the conductive paste composition. Within this range, there is no problem of electrode reliability such as electrode dropout and there is an effect that the contact resistance is significantly reduced. Preferably, it may be included in 3 to 7.5% by weight.

2-functional  ( Meta ) Acrylate  compound

The bifunctional (meth) acrylate compound may comprise an oligomer having two (meth) acrylate functional groups at both ends. The weight average molecular weight of the bifunctional (meth) acrylate compound may be 100 to 1,500 g / mol, preferably 100 to 500 g / mol, more preferably 200 to 300 g / mol.

The bifunctional (meth) acrylate compound is not particularly limited, but for example 1,6-hexanedioldiacrylate, 1,9-nonanedioldiacrylate, 1,10-decanedioldiacrylate, dipropylene glycol Diacrylate, tripropylene glycol diacrylate, polyethylene glycol diacrylate, polypropylene glycol diacrylate, polybutylene glycol diacrylate, 2-hydroxy-1-acryloxy-3-methadyloxypropane, pro Foxyrated ethoxylated bis-A diacrylate, 2,2 bis [4- (acryloxy polyethoxy) phenyl] propane, 2,2-bis [4- (acryloxy diethoxy) phenyl] propane, 9,9-bis [4- (2-acryloyloxy ethoxy) phenyl] fluorene, 2,2-bis [4- (acryloxy polypropoxy) phenyl] propane and tricyclodecane dimethanol diacrylate One or more selected from the group consisting of can be used.

The "acrylate" may mean both acrylate and methacrylate.

The bifunctional (meth) acrylate compound may be included in 0.1 to 10% by weight, preferably 0.5 to 6% by weight, more preferably 1 to 3% by weight in the conductive paste composition. Within this range, the peel strength for the conductive adhesive film can be high and the electrical properties can be improved.

The bifunctional (meth) acrylate compound may be included in an amount of 5 to 50 parts by weight, preferably 10 to 40 parts by weight, based on 100 parts by weight of the epoxy-based binder resin and the bifunctional (meth) acrylate compound. Within this range, the peel strength for the conductive adhesive film can be high and the electrical properties can be improved.

Conductive powder

The conductive powder may be any organic, inorganic or mixture thereof having conductivity.

The conductive powder is, for example, silver (Ag), gold (Au), palladium (Pd), platinum (Pt), copper (Cu), chromium (Cr), cobalt (Co), aluminum (Al), tin (Sn). ), Lead (Pb), zinc (Zn), iron (Fe), iridium (Ir), osmium (Os), rhodium (Rh), tungsten (W), molybdenum (Mo), nickel (Ni) and the like can be used. have. The conductive powder may be one or a mixture of two or more kinds, and at least two types may be alloyed. Preferably, the conductive powder includes silver particles, and may further include nickel (Ni), cobalt (Co), iron (Fe), zinc (Zn), or copper (Cu) in addition to the silver particles.

The conductive powder may include, but is not limited to, spherical powder, plate powder or mixtures thereof. Spherical powders include particles having a substantially spherical or elliptical shape. Spherical powder may have an average particle diameter (D50) of 0.1 to 2 ㎛. The plate powder has a flake or flat shape in the form of thin pieces. The average particle diameter (D50) of the plate-shaped powder may be 1 to 3 ㎛. There is an effect that the contact resistance and the line resistance is lowered within the above range.

The conductive powder may be included in an amount of 80 to 95 wt% in the conductive paste composition. Within this range, the contact resistance and the line resistance are lowered.

Hardener

Curing agents may include imidazole curing agents, amine curing agents, carboxyhydrazines, latent curing agents and modified phenolic resins. The curing agent may be included in 0.1 to 2% by weight, preferably 0.1 to 0.5% by weight of the conductive paste composition.

solvent

A solvent can melt | dissolve epoxy-type binder resin or a bifunctional (meth) acrylate compound, and what can be mixed with conductive powder and other additives can be used. For example, a solvent having a boiling point of 200 ° C. or more can be used. As the solvent, those commonly used in electrode production such as aliphatic alcohols, esters, carbitol solvents, cellosolve solvents, and hydrocarbon solvents can be used. For example, the solvent may be butyl carbitol acetate, methyl cellosolve, ethyl cellosolve, butyl cellosolve, aliphatic alcohol, terpineol, ethylene glycol, ethylene glycol mono butyl ether, butyl cellosolve acetate, texanol ( texanol) and the like. The solvent may be included in the balance.

The conductive paste composition of the present invention is a (meth) acrylic resin, a cellulose resin, an ester resin, which is used as a binder resin in related fields, in addition to an epoxy binder resin, a bifunctional (meth) acrylate compound, a conductive powder, a curing agent and a solvent. , Alkyd resin, butyral resin or PVA resin may be further included. The binder resin may be included in an amount of 1 to 10 parts by weight based on 100 parts by weight of the conductive paste composition.

The conductive paste composition of the present invention may further include at least one additive such as a diluent, glass frit, dispersant, thixotropic agent, viscosity stabilizer, antifoaming agent, pigment, UV stabilizer, antioxidant, inorganic filler and coupling agent. Can be. Such additives are well known to those skilled in the art and can be purchased commercially.

The conductive paste composition of the present invention can be used for forming electrodes of various electric and electronic materials, or for packaging or assembly, screen printing for electric and electronic device parts, and the like. For example, the conductive paste composition of the present invention requires low temperature properties and lowers contact resistance and line resistance, so that the conductive paste composition can be preferably used for electrodes of HIT solar cells or thin film solar cells.

The present invention relates to an electrode formed from the conductive paste composition. Methods of making such electrodes are commonly known to those skilled in the art. For example, the electrode may be prepared by printing the conductive paste composition and curing the printed paste. Curing may be performed at a temperature of 100 to 250 ° C., but is not limited thereto. The electrode may have a contact resistance of 0.1 to 2 mPa · cm ² , for example, 0.2 to 1 mPa · cm ² . The electrode may have a wire resistance of 30 to 60 mA / m, for example 40 to 50 mA / m.

Hereinafter, the configuration and operation of the present invention through the preferred embodiment of the present invention will be described in more detail. It is to be understood, however, that the same is by way of illustration and example only and is not to be construed in a limiting sense.

Details that are not described herein will be omitted since those skilled in the art can sufficiently infer technically.

Specific specifications of the components used in the following examples and comparative examples are as follows.

(1) As the epoxy resin binder resin, cresol novolac-based YDCN-10P (national chemical) (EPC resin A) and bisphenol F-based YDF-170 (national chemical) (epoxy resin B) were used.

(2) A 1,6-hexanediol diacrylate (Sinka Kamura, weight average molecular weight 226 g / mol) was used as a bifunctional (meth) acrylate compound.

(3) As conductive powders, silver particles of 241 grade (Technic) (a), HP0202E (diluent metal) (b), and 2-1C (Dowa) (c) were used.

(4) 2-undecylimidazole (C11Z grade, SHIKOKU Chemical) was used as a hardener.

(5) Butyl carbitol acetate (BCA) was used as a solvent.

Example  1-3

To prepare a conductive paste composition according to the composition of Table 1. The conductive paste composition was applied by rolling with a scraper on the screen plate, and printed with a squeeze while discharging to the wire portion of the screen plate. The electrode was prepared by curing at 200 ° C. for 40 minutes.

Comparative Example  1-3

An electrode was manufactured in the same manner as in Example 1-3, except that the composition of the conductive paste composition was changed as shown in Table 1 below.

Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Epoxy resin A 4.0 5.6 2.4 5.5 - 2.9 B 2.3 1.6 3 2.9 2.9 - Bifunctional (meth) acrylate compound 2.1 1.2 3 - 5.5 5.5 conductivity
powder a 22 22 22 22 22 22 b 22 22 22 22 22 22 c 44.3 44.3 44.3 44.3 44.3 44.3 Hardener 0.3 0.3 0.3 0.3 0.3 0.3 solvent 3 3 3 3 3 3

* Unit: weight%

Experimental Example Physical property evaluation

The electrodes prepared in Examples and Comparative Examples were used as samples, and physical properties were evaluated, and are shown in Table 2 below.

≪ Method for measuring physical properties &

1) Contact resistance: Obtain the 14 resistance values by increasing the pattern width from 0.02cm to 0.40cm by 0.02cm in a pattern of 500㎛ width 0.2cm in length, and then plot the graph to obtain slope, Rc and Lt values. After that, the contact resistivity value p was calculated using the following equation.

ρc = Rsh x (Lt) ²

Where Rsh is the product of the slope times W and W represents the length of the pattern.

2) Wire resistance: The wire resistance was measured using the multimeter using the electrode pattern of width 90micrometer length 100cm.

3) Peel strength: Peel strength was measured using a universal testing machine (UTM) (Hounsfield, H5KT). The 100N load cell was mounted, the grip was installed, the electrode was fixed to the grip, and the peel strength was measured under the tensile test speed of 50 mm / min.

Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Contact resistance
(mΩ · cm ²⁾ 0.48 0.2 0.9 1.0 5.8 7.6 Line resistance
(M / m) 40.3 43.3 46.2 67.3 34.4 46.2 Peel Strength (N) 3 3 3 3 3 3

As shown in Table 2, it can be seen that the electrode prepared from the conductive paste composition of the present invention has a low contact resistance and a line resistance while maintaining excellent peel strength with the conductive film compared to the comparative example.

Claims (14)

A conductive paste composition comprising two or more epoxy binder resins, a bifunctional (meth) acrylate compound, a conductive powder, a curing agent, and a solvent.
The method of claim 1, wherein the bifunctional (meth) acrylate compound is 1,6-hexanediol diacrylate, 1,9-nonanediol diacrylate, 1,10-decanediol diacrylate, dipropylene glycol di Acrylate, tripropylene glycol diacrylate, polyethylene glycol diacrylate, polypropylene glycol diacrylate, polybutylene glycol diacrylate, 2-hydroxy-1-acryloxy-3- metharyloxypropane, propoxy Rated ethoxylated bis-A diacrylate, 2,2 bis [4- (acryloxy polyethoxy) phenyl] propane, 2,2-bis [4- (acryloxy diethoxy) phenyl] propane, 9 ,, 9-bis [4- (2-acryloyloxy ethoxy) phenyl] fluorene, 2,2-bis [4- (acryloxy polypropoxy) phenyl] propane and tricyclodecane dimethanol diacrylate A conductive fere characterized in that at least one member selected from the group consisting of Yeast composition.
The conductive paste composition of claim 1, wherein the bifunctional (meth) acrylate compound is included in an amount of 0.1 to 10% by weight of the conductive paste composition.
The conductive paste composition of claim 1, wherein the bifunctional (meth) acrylate compound is included in an amount of 5 to 50 parts by weight based on 100 parts by weight of the total amount of the epoxy-based binder resin and the bifunctional (meth) acrylate compound. .
The conductive paste composition of claim 1, wherein a weight average molecular weight of the bifunctional (meth) acrylate compound is 100 to 1,500 g / mol.
The epoxy binder resin according to claim 1, wherein the epoxy binder resin is at least one epoxy binder resin (A) having a melt viscosity of 1.5 Pa.s or less at 150 ° C and an epoxy having a melt viscosity of 10 Pa.s or less at 25 ° C. A conductive paste composition comprising at least one binder resin (B).
The epoxy binder resin (A) is at least one selected from the group consisting of cresol novolac resins, biphenyl resins, biphenyl mixed resins, naphthalene resins and dicyclopentadiene resins. A conductive paste composition comprising a.
The conductive paste composition according to claim 6, wherein the epoxy binder resin (B) comprises at least one member selected from the group consisting of bisphenol F resin and bisphenol A resin.
The conductive paste composition according to claim 6, wherein the epoxy binder resin comprises a cresol novolac resin as an epoxy binder resin (A) and a bisphenol F resin as an epoxy binder resin (B).
The conductive paste composition of claim 6, wherein the epoxy binder resin comprises an epoxy binder resin (A) and an epoxy binder resin (B) in a weight ratio of 1: 0.1 to 1:14.
The method of claim 1,
The conductive paste composition
1 to 10% by weight epoxy-based binder resin;
0.1 to 10% by weight of a bifunctional (meth) acrylate compound,
80 to 95% by weight of conductive powder,
0.1 to 2% by weight of a curing agent, and
A conductive paste composition comprising a residual amount of solvent.
The method of claim 1, wherein the conductive paste composition further comprises one or more selected from the group consisting of (meth) acrylic resins, cellulose resins, ester resins, alkyd resins, butyral resins and PVA resins. Conductive paste composition.
An electrode formed from the conductive paste composition of any one of claims 1-12.
The electrode according to claim 13, wherein the electrode has a contact resistance of 0.1 to 2 mPa · cm ² and a line resistance of 30 to 60 mA / m.